IMPACT OF TRAINING AND COMPETITION LOAD ON NEUROMUSCULAR RECOVERY, HORMONAL RESPONSE AND MATCH PERFORMANCE IN ASSOCIATION FOOTBALL by AMBER ELLISE ROWELL This thesis is submitted in partial fulfilment of the requirements for the award of DOCTOR OF PHILOSOPHY Supervisor: Professor Robert J.A. Aughey Co-supervisors: Associate Professor Stuart J. Cormack and Professor Andrew M. Stewart. Institute of Health and Sport (IHES) College of Sport & Exercise Science Victoria University 2018 iii ABSTRACT In team sports, the competition season requires a balance between training and recovery. To assist in this process, both internal and external load are quantified. External load can be measured using Global Positioning Systems (GPS) and sensors such as accelerometers. Internal load is commonly identified through session rating of perceived exertion (sRPE), biochemical response in addition to changes in performance tests. However, little is known about the interaction between training load, the response to this load, and performance. Study 1 determined the response of countermovement jump (CMJ) performance and salivary testosterone and cortisol to low, medium and high accelerometer derived PlayerLoad™ following football match play. Flight time:contraction time (FT:CT) was the most sensitive CMJ metric, with a dose-response reduction for 42h post-match. There were post-match increases in testosterone and cortisol irrespective of PlayerLoad™ level, and substantial variability which limits the usefulness of hormonal markers. Study 2 assessed the impact of training and competition load throughout a professional football season on FT:CT, testosterone, cortisol and testosterone:cortisol and match performance. The largest effects of internal load on performance occurred in the 3- to 14- day pre-match window. An association between increased load and lower rating of performance was identified in defenders, whilst strikers and wide midfielder’s performance rating was higher with higher load. Change in load did not substantially impact FT:CT or the hormonal response, and there was limited impact of these measures on performance. Study 3 examined the use of a commonly used football training drill; small sided game (SSG), for measurement of neuromuscular fatigue (NMF). Whilst high weekly load increased accelerometer derived metrics during the SSG, these modifications did not appear to be fatigue related. Lower FT:CT compared to baseline, was related to iv reductions in accelerometer derived variables during the SSG. The reductions in FT:CT and accelerometer variables in the SSG were followed by the same modifications to match activity profile. Therefore, a standardised SSG game may be a useful tool for the assessment of NMF. This thesis provides insights into the links between training and competition load, the response to that load, and the impact on performance in elite male football players. The results offer practitioners useful approaches to monitor athletes and maximise their performance. Finally, this thesis demonstrates the utility of an SSG for the assessment of NMF. v STUDENT DECLARATION “I, Amber Ellise Rowell, declare that the PhD thesis entitled “Impact of Training and Competition Load on Neuromuscular Recovery, Hormonal Response and Match Performance in Association Football” is no more than 100,000 words in length including quotes and exclusive of tables, figures, appendices, bibliography, references and footnotes. This thesis contains no material that has been submitted previously, in whole or in part, for the award of any other academic degree or diploma. Except where otherwise indicated, this thesis is my own work”. Signature Date 09th March 2018 vi ACKNOWLEDGEMENTS With the thesis now complete, I can reflect on what has been one of the most challenging yet amazing journeys. The transformation and personal growth that I have experienced throughout this PhD has been something that I never imagined would happen. I have learnt so much, not only intellectually with the material covered in this thesis but also on a personal level. The doubt I had in myself and my ability to achieve this was a constant battle that I had to overcome. I am beyond proud that I persisted and preserved when the easy option would have been to quit, and now seeing this through to completion I am overwhelmed with joy. Professionally, this PhD has provided me the opportunity to work within an elite football team, present at international and Australian based conferences and receive invitations to present at the Seattle Sounders Sports Science seminar as well as to the football and medical department at Arsenal Football Club. Without the support of some extremely intelligent and influential people to motivate and mentor me, I wouldn’t have had the ability to complete this. Firstly thank you to Victoria University and also to Australian Catholic University for the opportunity to conduct my research, the scholarship from Victoria University and the access to facilities at both universities. To my primary supervisor Rob, you intimidate me with your wealth of impeccable knowledge, and your extensive experience in this field. What a journey this has been from undergraduate through to honours and now the PhD. You have been an excellent mentor and someone who I will always regard so highly and look up to. Thank you for being my supervisor and guiding me through this process. I know it hasn’t necessarily been an easy one, and along the way there has been some challenging moments. But during the challenges, the guidance and support you gave me, without judgement and the overall vii belief you have shown in me I will always appreciate. I have no doubt our paths will cross again in the future and wish only great success for you and your family. To Stu, the work and unquestioned commitment you have shown me throughout every process I will forever be so appreciative of. Most importantly, you taught me to believe in myself and my abilities. I will always be in debt to you and the commitment you have given to this. You have been a truly great mentor and someone I hold in such high regard as well as being a great friend, thank you for everything. To the players and staff at the Melbourne Victory Football Club, thank you for the support by allowing me to conduct my PhD research, as well as the opportunity to be involved in the club for 8 seasons and take over the lead Sports Science position. To the players, thank you so much for allowing me to utilise your data for my PhD research. You were all so supportive of me and had a genuine interest in the research and results. To Anthony DiPietro and the extended board members, thank you for the contribution to my scholarship and allowing me to conduct my research within the club. To the coaches, fitness and medical staff I have worked alongside, with a special mention to Anita Pedrana, Ernie Merrick, Ange Postecoglou, Kevin Muscat, Pete Cklamovski, JP, Travis Maude, Ryan Florence-Reinets and Krishant Nadu thank you for what you taught me about the art of football coaching along with injury prevention and treatment. Thank you for supporting my research and showing a genuine interest in the application of results. Special mention also to Aaron and Guido for your friendship and the much needed laugh along the way! To my friend and mentor Anth, thank you so much for having the belief in me and what I do. You taught me so much about football, and life skills, and you gave me the support for my work which I am so appreciative of. I look forward to working with you again in the future. viii There are three special friends and colleagues who have meant so much to me and been there from the start to the end, Kristal, Alice and Maty thank you all so much for being such amazing friends and supporting me throughout. We are the originals and without your support, I would not have been able to get through. You all deserve every bit of success in life that comes your way. To the rest of my research team and friends at VU and ACU, I sincerely wish the best of luck to all of you with your future endeavours and journeys through life. To Ryan, thank you for being a constant support and special friend who I know I can always turn to when I need. You are always looking out for me and creating opportunities for me and I hope you know how much that is appreciated. To Will and Andy, thank you both for your support in this PhD. Especially to you Will for your substantial statistical contribution to this research, you are a pure genius! Importantly you made complicated statistical analysis easy to understand and interpret, and we were able to share some great laughs along the way. To my best friend Kahlia, thank you so very much for all the coffee and brunch catch ups and for letting me stay at your house and look after Boris and Hugo when I needed some time and space. You are such an amazing and beautiful friend, thank you for just being there. To Emily and Lozza, thank you girls also for being there for me. I have so appreciated having your friendship and support. Lastly, the biggest dedication goes to the three most important people in my life and my pillars of support, my parents Geoff and Gael and my sister Zoe. I can’t begin to express in writing how much you have unselfishly given me throughout this journey. The unquestionable support, love and encouragement you have all shown me along the way, for picking me up every time I crumbled to pieces I will forever be truly appreciative of. I know the stress of this PhD has been difficult for you all to deal with at times, and we ix have all had personal challenges throughout.